It is estimated that between 5% and 10% of patients admitted to hospitals acquire one or more healthcare-associated infections, which leads to more than a million people worldwide being affected by infections acquired in hospitals. Health-care associated infections are also an important problem in extended care facilities, including nursing homes and rehabilitations units. These health-care acquired infections are associated with nearly 100,000 deaths annularly.
Patients infected with healthcare-associated microbes frequently contaminate items in their immediate vicinity with microbes that may remain viable on surfaces for days to weeks. Contaminated surfaces in healthcare facilities contribute to the spread of healthcare-associated microbes. In some instances, patients acquire microbes following direct contact with contaminated equipment or other surfaces. Contaminated surfaces can act as sources from which healthcare workers contaminate their hands. Healthcare workers can contaminate their hands by touching contaminated surfaces, and can transmit microbes if their hands are not cleansed appropriately.
Inadequate cleaning of rooms after discharging a patient with certain contagious diseases put subsequent patients admitted to the room at risk of acquiring the organism. Routine cleaning of patient rooms is often below the required standard. Therefore, improved cleaning and disinfection of the environment can reduce the risk of patients acquiring multi-drug resistant microbes. Cleaning, disinfecting and sterilization save lives and improve patient outcomes. Providing patients with a safe environment of care requires appropriate cleaning and disinfection of medical equipment and environmental surfaces.
Furthermore, many microbes can form multicellular coatings, called biofilms. Biofilms are any group of microorganisms in which cells stick to each other on a surface. Biofilms can facilitate the proliferation and transmission of microorganisms by providing a stable protective environment. Biofilms can be prevalent in facilities such as hospitals, schools, public restrooms, restaurants, bars, club houses, and daycare centers.
Accordingly, much research has been devoted toward preventing colonization of microbes on the surfaces in such facilities, especially healthcare facilities, and preventing growth of bacteria by the use of antimicrobial agents. Various types of antimicrobials, such as triclosan and silver, have been in use for many years.
The most common antimicrobial being incorporated into materials is silver. Silver is a powerful, natural antibiotic and is one of the oldest antimicrobial agents on record. Silver derives its broad spectrum antimicrobial activity from the ability of silver ions. Silver ions released from the antimicrobial agent, come in contact with microbes and the microbes are inhibited.
With the presence of moisture, the antimicrobial additives release a few silver ions gradually. Silver ions have an ability to strongly bind to the cellular enzyme of microbes and inhibit enzyme activity of the cell wall, membrane, and nucleic acids. As microbes have a negative surface charge, silver ions with a positive charge are drawn toward the microbes, and disturb their electric balance and disrupts their electron transfer. The result is that the microbes burst their cell walls and are extinguished.
Otherwise, silver ions are taken into the microbes where they react and bond to the cellular enzyme microbes. Acting as a catalyst, silver disables the enzyme that one-cell bacteria, viruses and fungi need for their oxygen metabolism. This inhibits enzyme activity and multiplication of the microbes by suffocation, thus resulting in death of the microbes.
Thus, antimicrobial agents have been found to be useful blended with materials such as plastics, paintings and coatings, which also have applications in facilities such as hospitals. In particular, such antimicrobial agents have been adapted for incorporation within plastic, paint, and coating compositions to produce industrial, consumer and household products, which exhibit antimicrobial characteristics.
Although silver is a powerful antimicrobial agent, these coatings of antimicrobial agent are not intended as a substitute for good hygiene. Coated products must still be cleaned to ensure the surfaces will be free of destructive microbes. Commercially available antimicrobial materials usually require regular cleaning every 3-4 days. This is because existing technologies like triclosan or ionic silver technologies require moisture to activate the reactions in order to reduce bacterial grow. After coming in contact with water, an antimicrobial material, for example silver, releases effective amount of silver ions to inhibit the growth of microbes. But more importantly, the build-up of dead microbes on the surfaces of the material prevents new microbes from making contact with the antimicrobial active ingredients. Therefore, the antimicrobial efficacy will decrease over time.
Thus, there remains a need for a system and method that provides lighting devices with effective antimicrobial activity in order to reduce the growth of bacteria, without increasing the antimicrobial levels, which are restricted by U.S. Environmental Protection Agency (EPA) and U.S. Food and Drug Administration (FDA) regulations. The EPA and FDA regulate antimicrobial products to assess the potential dangers and risks to human health and the environment.
Currently, there are more than 5,000 antimicrobial products registered with the EPA and sold in the marketplace. Nearly 60 percent of antimicrobial products are registered to control infectious microorganisms in hospitals and other health care environments.
Because antimicrobials are considered pesticides, regulation of antimicrobial plastic additives in the U.S. is generally the domain of the EPA under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). If a product claims to be effective in controlling specific microorganisms (such as, E. coli, S. aureus, and Salmonella), it must be registered as a pesticide because the EPA considers this a public health claim. The EPA regulations do not cover the use of antimicrobials in medications or food additives.
The FDA has broad jurisdiction to regulate the safety and effectiveness of products that constitute foods, dietary supplements, cosmetics, drugs, biological, or medical device products. Where antimicrobial claims in labeling or advertising are made stating that the product is intended for use in the prevention or mitigation of disease in man or animals, such products are subject to FDA regulations.
There are some antimicrobial additives for which the proposed uses are regulated by the FDA as food additives and regulated by the EPA as pesticides. In this case, there are joint regulations where the antimicrobial product may have to comply with the requirements of both the EPA and FDA.